FbxHashMap< KEY, VALUE, HASH, Destruct, Comparator > Class Template Reference

#include <fbxhashmap.h>

Class Description

template<typename KEY, typename VALUE, typename HASH, class Destruct = FbxNoOpDestruct<VALUE>, class Comparator = FbxDefaultComparator<KEY>>
class FbxHashMap< KEY, VALUE, HASH, Destruct, Comparator >

This object represents a standard hash map.

You must provide the typename of KEY and VALUE as well as the typename of the class that contains the hash function to use to hash values. The hash class must overload operator() and be built like this.

class SimpleHash
{
public:
    inline unsigned int operator() ( const int pKey ) const
    {
        return pKey;
    }
};

Definition at line 45 of file fbxhashmap.h.

Classes
class	Iterator
	Iterate through every element in a hash map. More...

Public Types
typedef KEY	KeyType
typedef VALUE	ValueType
typedef HASH	HashFunctorType

Public Member Functions
	FbxHashMap (int pBucketSize)
	Construct a FbxHashMap with an user-defined maximum number of elements. More...
	FbxHashMap ()
	Construct a FbxHashMap with the default maximum number of elements (30) More...
	~FbxHashMap ()
	Clear all elements in the hash map before destroying itself. More...
void	Clear ()
	Calls operator delete on all elements of the hashmap, de-allocating all memory and destroying them. More...
const Iterator	Find (const KeyType &pKey) const
	Find an element in the hashmap. More...
VALUE	Remove (const KEY &pKey)
	Remove an element in the hashmap. More...
ValueType &	operator[] (const KeyType &pKey)
	Add or retrieve a KeyValuePair from the Hashmap. More...
Iterator	Start () const
	Returns an iterator pointing on the first non-null element in the map. More...
Iterator	End () const
	Returns an iterator pointing on the last element in the map. More...

Friends
class	Iterator

Member Typedef Documentation

KeyType

typedef KEY KeyType

Definition at line 48 of file fbxhashmap.h.

ValueType

typedef VALUE ValueType

Definition at line 49 of file fbxhashmap.h.

HashFunctorType

typedef HASH HashFunctorType

Definition at line 50 of file fbxhashmap.h.

Constructor & Destructor Documentation

FbxHashMap() [1/2]

FbxHashMap ( int  pBucketSize )

inline

Construct a FbxHashMap with an user-defined maximum number of elements.

Parameters

pBucketSize

Initial maximum number of elements.

Definition at line 213 of file fbxhashmap.h.

    {
        mBuckets.Resize( pBucketSize );
    }

FbxHashMap() [2/2]

FbxHashMap ( )

inline

Construct a FbxHashMap with the default maximum number of elements (30)

Definition at line 221 of file fbxhashmap.h.

    {
        mBuckets.Resize(30);
    }

~FbxHashMap()

~FbxHashMap ( )

inline

Clear all elements in the hash map before destroying itself.

Definition at line 229 of file fbxhashmap.h.

    {
        Clear();
        mBuckets.Clear();
    }

Member Function Documentation

Clear()

void Clear ( )

inline

Calls operator delete on all elements of the hashmap, de-allocating all memory and destroying them.

Definition at line 238 of file fbxhashmap.h.

    {
        for( int i = 0; i < mBuckets.GetCount(); ++i)
        {
            if( mBuckets[i] )
            {
                ListItem* lNext = mBuckets[i]->mNext;
                while( lNext )
                {
                    ListItem* lNextNext = lNext->mNext;
                    FbxDelete(lNext);
                    lNext = lNextNext;
                }

                FbxDelete(mBuckets[i]);
                mBuckets[i] = NULL;
            }
        }
    }

Find()

const Iterator Find ( const KeyType &  pKey ) const

inline

Find an element in the hashmap.

If no element exist with the specified key, returns an iterator pointing on the end of the map (not an actual KeyValuePair).

Parameters

pKey	The value of the key corresponding to the element

Returns

An Iterator referencing that element

Definition at line 264 of file fbxhashmap.h.

    {
        unsigned int lIndex = mHashFunctor(pKey);
        lIndex = lIndex % mBuckets.GetCount();
        ListItem* lItem = mBuckets[lIndex];
        while( lItem )
        {
            if( Comparator::CompareIt( lItem->mKey, pKey ) )
            {
                Iterator lIt( this, lIndex, lItem );
                return lIt;
            }
            lItem = lItem->mNext;
        }
        
        return End();
    }

Remove()

VALUE Remove ( const KEY &  pKey )

inline

Remove an element in the hashmap.

Parameters

pKey	The key value of the element to remove

Returns

The value of the element that was just deleted. If the element does not exist, a value created with its default constructor will be returned

Definition at line 287 of file fbxhashmap.h.

    {
        unsigned int lIndex = mHashFunctor(pKey);
        lIndex = lIndex % mBuckets.GetCount();
        ListItem* lItem = mBuckets.GetAt(lIndex);
        ListItem* lLastItem = NULL;
        
        while( lItem )
        {
            if( lItem->mKey == pKey )
            {
                if( lLastItem )
                    lLastItem->mNext = lItem->mNext;

                if( mBuckets.GetAt(lIndex) == lItem ) 
                    mBuckets.SetAt(lIndex, lItem->mNext );

                VALUE lValue = lItem->mValue;
                FbxDelete(lItem);
                
                return lValue;
            }

            lLastItem = lItem;
            lItem = lItem->mNext;
        }
        
        return VALUE();
    }

operator[]()

ValueType& operator[] ( const KeyType &  pKey )

inline

Add or retrieve a KeyValuePair from the Hashmap.

If there is already an entry in the map for an element with key value specified in parameter, the value will be returned. Otherwise, a new entry will be created with this key value and the default value for ValueType will be returned. It can be modified using the assignment operator

Parameters

pKey	The key for which to retrieve/add a value.

Returns

Value of the element referenced by the key specified in parameter.

Definition at line 324 of file fbxhashmap.h.

    {
        unsigned int lIndex = 0;
        Iterator lIt = InternalFind( pKey, lIndex);
        if( lIt != End() )
        {
            return lIt.mCurrentItem->mValue;
        }

        lIndex = lIndex % mBuckets.GetCount();
        ListItem* lItem = FbxNew< ListItem >();
        lItem->mNext = NULL;
        lItem->mKey = pKey;

        if( !mBuckets.GetAt(lIndex) )
        {
            mBuckets.SetAt(lIndex, lItem);
        }
        else
        {
            lItem->mNext = mBuckets.GetAt(lIndex);
            mBuckets.SetAt(lIndex, lItem);
        }

        return lItem->mValue;
    }

Start()

Iterator Start ( ) const

inline

Returns an iterator pointing on the first non-null element in the map.

Returns

An iterator pointing on the first non-null element in the map.

Definition at line 354 of file fbxhashmap.h.

    {
        for( int i = 0; i < mBuckets.GetCount(); ++i )
        {
            if( mBuckets[i] )
            {
                Iterator lIt( this, i, mBuckets[i] );
                return lIt;
            }
        }

        return End();
    }

End()

Iterator End ( ) const

inline

Returns an iterator pointing on the last element in the map.

This is not an actual KeyValuePair but but an iterator pointing on a null element.

Returns

Iterator pointing on a null value at the end of the map

Definition at line 372 of file fbxhashmap.h.

    {
        Iterator lIt( this, 0, NULL );
        return lIt;
    }

Friends And Related Function Documentation

Iterator

friend class Iterator

friend

Definition at line 406 of file fbxhashmap.h.

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The documentation for this class was generated from the following file:

• fbxsdk/core/base/fbxhashmap.h